Microbubbles size distribution

The retention time in the flotation chamber is usually about 3 to 5 min, depending on the characteristics of the process water and the performance of the flotation unit. The process effectiveness depends upon the attachment of air bubbles to the particles to be removed from the process water.57 The attraction between the air bubbles and particles is primarily a result of the particle surface charges and bubble size distribution. The more uniform the distribution of water and microbubbles, the shallower the flotation unit can be. 

Size distribution plays a major role in the microbubble stability, behavior in vivo, and the microbubble acoustic response. The Rayleigh-Plesset equation which describes the microbubble response to pressure waves suggests that ultrasound scattering is proportional to the sixth power of the microbubble diameter [46]. It is not possible, however, to inject large bubbles (e.g., 0.1 or 1 mm in diameter) in the bloodstream, because they would be immediately lodged in the vasculature as emboli, severely limiting the blood flow. Fortunately, microbubbles with the size of several micrometers are still quite echogenic in the ultrasound... 

Fig. 9.2. Relative size distribution of artificial microbubbles in an unstirred medium. Light-scatter signals were collected over a total period of 1,000 sec, and plotted in three (part A) and two (part B) dimensions. (See text for further discussion.)...

SIZE DISTRIBUTION OF SYNTHETIC MICROBUBBLES FORMATION, COALESCENCE, FISSION, AND DISAPPEARANCE... 

Bimodal size distribution of the microbubble-surfactant particle population... 

Fig. 10.1. Particle size distribution determined for artificial, surfactant-stabilized microbubbles (and micelles) in distilled water.

In summary, the size distribution of LCM in deionized water was measured using several analytical techniques. The Filmix agent was found to contain close to 1010 LCM/ml >0.1 pm, when measured using optical particle counters. A large majority ( 90%) of the LCM (i.e., Filmix coated-microbubbles/particles ) were smaller than 0.2 pm in diameter. 

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